depends on the team.

It usually takes between 8 and 20 hours of actual work, depending on the series, the skill of the people working on it, the desired quality, and the complexity and volume of dialogue.

But that's 8 to 20 hours of work spread across between 4 and 10 people (usually 6-7 people is about average for most teams). Meaning if schedules don't line up, or if someone's got other things to do (like live their lives), that 8 to 20 hours can be spread over more than a week pretty easily.

I've been sitting on a half-done edit of the one show I'm working on for like 4 days, while just sort of mulling over what the series means (it's sort of hard to interpret correctly), and while maintaining my job and a reasonable degree of sanity. It's really easy for a single episode to overflow a week of work, and the next episode to air before you're done working on the current one.

I'd say the median case for a normal fansub is probably in the neighborhood of 5 days from air to release.